The Great Dune of Pyla: A Moving Desert in France

The Great Dune of Pyla, located 60 km from Bordeaux in the Arcachon Bay area, France, happens to be the tallest sand dune in Europe. Also known as Great Dune of Pilat, the sand dune is enormous - measuring 500 meter in width, 3 km in length and rising to a height of 107 meter above sea level. Because of the dune’s unexpected location and beauty, it is a famous tourist destination with more than one million visitors per year.

Interestingly, the dune is relentlessly moving inwards, slowly pushing the forest back to cover houses, roads and even portions of the Atlantic Wall. The rate of movement is discontinuous; sometimes it moves fast (10 meter in a year) and sometimes very slow (less than a meter). During the last 57 years, the dune has moved some 280 meter giving an annual displacement of 4.9 meter per year.

This migration of the Great Dune has covered nearly twenty private properties, and each year the sand of the east slope of the dune covers 8000 square meter of the surrounding pine forest. At the North East part of the dune, a road was overlapped in 1987 after an avalanche of sand, and buried in 1991. An example of a house buried over the dune is cited in a newspaper in September 19, 1936. At the South East of the dune, a Bordeaux family had decided to have a villa built in 1928. Two years later, the sands began to invade the house and by 1936, the house had completely disappeared over the sands.

Maritime winds explain both that mobility and the shape of the dune; it offers soft slopes on the ocean side and an abrupt face on its east side, the forest side. For the most athletic visitors, climbing up this slope is a real challenge. For the others, a staircase makes the ascent a little easier. At the top, the view is spectacular – the sea coast, the vast pine forest of Les Landes and, when the whether is clear, the Pyrennees range